Double contingency transmission outages in a generation and reactive power deficient area

A methodology is described that studies all N-2 outages-instead of selecting specific N-2 double contingency events-and possibly missing some critical ones. Using a power flow program and the capabilities, power and speed of modern computers, a case study was performed for more than 25000 N-2 outages of a 230 kV system in a generation and reactive power deficient area. The data generated by the computer rims was stored in a database program, and reports were generated using different "queries" for analyzing the data. The results of the N-2 outage studies were directly applicable to the analysis and selection of undervoltage relay settings for load shedding. The performance of critical buses for which the power flow simulation diverges was studied with V-Q analysis.